Return or counterbalance for punch press controls



March 26, 1940. G. O. JOHNSON RETURN OR COUNTERBALANCE FOR PUNCH PRESS CONTROLS I Original Filed April 1, 1938 INVENTOR. 640/01/ 0, cfo/mJo/r BY E l/M 4" 4Z2 W Patented Mar. 1940 Y RETURN on COUNTERBALANCE FOR- PUNCH a r PRESS, CONTROLS I fiustav 0. Johnson, Eikhart, Ind. Original application April 1, 1938, Serial No. j 1219;471. Divided fund this application March I c.1939. Serial No. 259,947

This invention relates to improvements in return or counterbalance for punch press controls.

This is a division of my application for patent Serial No. 199,471 for improvements inPunch e press controls, filed April 1, 1938.

The main object of the present invention is to provide 'a punch press control embodying a return or counterbalance mechanism fora punch press control actuating link, the elements it of which are readily removable and quicklygreplaceable without stopping the machine, if such is desired or necessary.

Further objects relatingto details and econ omies of the invention will appear from the de- 7? scription to follow. The" invention is definedin the claims.

A structure embodying the features of my invention is illustrated in the accompanying drawing, wherein: a

n Fig. 1 is a perspective view of a treadle operated punch press equipped with a .single-revolution control embodying the link return or counterbalance mechanism of the present invention.

Fig. 2 is an enlarged fragmentary view in side an elevation illustrating the construction and .ar-

rangement of the return: mechanism herein laimed. a

Fig. 3 is an enlarged fragmentary yiew partially in section on line of Fig. 2, further i1lustrat- 3o ing details of the construction.

' In the above identified application I illustrate.

and describe in particular a single-revolution control means, herein designated generally I, for a I treadle operated punch press 2, which control 35 means positively declutches the punch ram after each punching operation so as to prevent another cycle until thetreadle has been allowed to return to raised position. The aforesaid control means I includes as a part thereof an actuating link 40 herein designated 3 having adjustably secured.

wise direction relative to the guides as the result I of actuation of follower 4 by the control element 4|. The follower is adjustably secured to the 50 link by means of a set screw 42.

Intermediate the follower 4 and guides 5,'the

link is provided with a notch 5| engageable with the pivot pin 52 of a toggle control connection or joint 53, being disengaged from said pin by 58 the aforesaid clockwise pivoting of the link and The link 3 extends being normally urged toward the pin by the counterbalance or return mechanism of they present invention, which is-generally designated 54. As described in the aforesaid parent application, when the link 3 'is actuated downwardly, it breaks the toggle connection 53 and a cycleof thepress operation commences. Thefollower 4 is engaged by control element 4| to disengage. notch 5| from the pivot pin 52, whereupon the toggle connection is. straightened by a counter. balance weight 6 thereon for a subsequent stoppage of the ram eccentric shaft in the manner described. in the aforesaid application. Forthe purpose of actuating link 3 downwardly, it (is connected at its lower end to a treadle 8. 'Thecounterbalance mechanism 54 of the present invention serves as means to elevate the linkand counterbalance the. same in'counterclockwise direction asviewed in Fig. 'lgwhen the treadle 8 is released, in order to again engagenotch 5| with pivot pin 52 of the. toggle connection 53 for a succeeding press operation. I Y

As clearly illustrated in Figs; '2 and 3, the return or counterbalance mechanism of my inven- .tion consists of a pair of coil compression'springs 9 interposed between a fixed abutment ID on the press frame and an adjustable abutment H 0.341?

'ried by link 3, these respective abutments being laterally offset from one another so as topermit a counterclockwise actuationof the link relative to guides 5 by the springs to urge the link against pivot pin 52, as well as an elevating of the link. The present invention is also concerned with an improved mounting'for springs 9, which enables the sameto be removed and replaced readily and quickly in case of breakage or for other reasonwithout necessarily stopping the operation of the press flywheel.

Referring in particular to Fig. 3, it will be seen that the springs are centered and held in 40 position by pairs of pins I2, 13 on abutments l0 and II respectively. The tubular sleeves I4 surround the springs 9 and are crimped inwardly at l5 at the bottoms thereof in order to enable the said springs to be compressed and removed from the pins l2 by simplyv lifting the springs, then removed from the pins [3 by a simple movement of withdrawal. In this manner, it is apparent that the springs may be removed and replaced with'a maximum of speed and a minimum of difiiculty without stopping the press. The abutment H is readilyv adjustable lengthwise of link 3 by means of a clamping arm "5 and a set screw I'l carried thereby, as illustrated in Fig. 2. It is therefore possible to regulate the thrust exerted by the springs 9 at will. Likewise, in the event it is desired to remove the link 3 entirely, this may be readily accomplished by loosening the set screws 42 and I1 and sliding the link out length- Wise.

The foregoing mechanism is a simple yet effective one for assuring an adequate actuation of the link 3 towards the left to enable theengagement thereof with the toggle mechanism when 'a press revolution has been completed, although I y it will be apparent that the advantageous features of replaceability of the springswith little difli culty recommend the construction for use in other connections.

I have illustrated and described my improvements in an embodiment which is verypractical;

I have not attempted to illustrate or describe other embodiments or adaptations as it is believed this disclosure will enable those skilledin the art to embody or adapt my improvements as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patentjisz" 1.1In a press of the type described, a clutch member adapted to connect and disconnect the press with a driving instrumentality therefor,

means for shifting said member into and out of operative position comprising treadle actuated link means, means for returning said link means to original position when the treadle is released comprising a fixed abutment and an f abutment carried by said link means, a spring engaging said abutments, pins on said abutments for pcsitioning and centering said spring, and a sleeve surrounding said spring and having provision for engaging and removing the same.

2. In a control means of the type described, a frame, an actuating link, treadle means for shifting said link longitudinally relative to the frame, means on said frame for guiding longitudinal movement of the link, means for returning the link'to original position when released by said treadle means comprising a pair of springs, abutments on said frame and link engaged by said springs, there being pins on said respective abutments for positioning and centering the springs,

and sleeves surrounding the springs to facilitate removal thereof, and means on said link abutment 'for adjusting the same and for loosening the same to permit removal of the link.

3. In a control means of the type described, a frame, an actuating link, treadle means for shifting said link longitudinally relative to the frame, means. on said frame-for guiding longitudinal movement of the link, means for returning the link to original position when released by said treadle means, comprising a thrust spring, abutments on said frame and link respectively engaged by said spring, there being pins on said respective abutments" for positioning and centering the spring, and a sleeve surrounding the spring to facilitate removal thereof.

4. A' counterbalance and return mechanism for a punch press control having an actuating link and means for shifting the link relative to the frame of the press, including means on said frame ,for. guiding longitudinal movement of the link under the influence of the link shifting means,

means for returning the link to original position when released by said link shifting means, said return means exerting a continuous counterbalancing force on the link in a lateral direction and including a pair of springs, abutments on the frame and link engaged by said springs, said abutments being laterally offset from one another whereby the springs urge the link laterally relative to the frame, pins on said abutments for positioning and centering thespringsand sleeves surrounding the springs to facilitate removal thereby by individual compression of the springs out of engagement with the pins.

5. A counterbalance and return mechanism for V a punch press control having an actuating link and means for shifting the link relative to the frame of the press, including means on said frame 

